Barrel stave edge sawing machine

ABSTRACT

A pair of motor driven circular saws are mounted on opposite sides of a frame supported horizontal barrel stave carrying conveyor with the axes of the saws perpendicular to the direction of conveyor travel and their planes arranged in downwardly converging relation. Spring loaded guide rollers, forming a part of the saw driving motor supports, adjusts the position of the saws in a desired barrel stave edge trimming spaced-apart relation by contact with the respective opposing longitudinal sides of a barrel stave to be trimmed as it is moved by the conveyor between the saws. Lock means actuated by spring loaded pressure rollers overlying the position of the barrel stave when moved by the conveyor maintains the adjusted spaced-apart relation of the saws for the duration of the saw trimming action on each side of each stave moved through the machine by the conveyor.

Jan. 16, 1973 United States Patent [I91 Busch [541 BARREL STAVE EDGE SAWING Primary Examiner-Donald R. Schran MACHINE Assistant Examiner-James F. Coan Attorney-Robert K. Rhea [76] Inventor: Bennie T. Busch, P. 0. Box 543 Mena, Ark. 71953 Dec. 28, 1970 Appl. No.: 101,569

[57] ABSTRACT A pair of motor driven circular saws are mounted on [22] Filed:

opposite sides of a frame supported horizontal barrel stave carrying conveyor with the axes of the saws perpendicular to the direction of conveyor travel and their planes arranged in downwardly converging rela- Rm 7 m 1 MR 8 R3 N4 1 8 2 l 7 4 C s U P 5 tion. Spring loaded guide rollers, forming a part of the saw driving motor supports, adjusts the position of the saws in a desired barrel stave edge trimming spacedapart relation by contact with the respective opposing 2 9 0A I 3 7 4 h -1 7R 2 k 0 R3 0 8 M MRw 6 mu 4 s r "a e S l...m d Ld .mF Hod 55 References m longitudinal sides of a barrel stave to be trimmed as it is moved by the conveyor between the saws. UNITED STATES PATENTS Lock means actuated by spring loaded pressure rollers overlying the position of the barrel stave when moved by the conveyor maintains the adjusted spaced-apart relation of the saws for the duration of the saw trimming action on each side of each stave moved through the machine by the conveyor.

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3,452,788 7/1969 Busch 3 Claims, 9 Drawing Figures PATENTEDJAH 16 I973 SHEET 1 BF 5 BEN N IE T. BUSCH INVENTOI? PATENTEDJAH 161975 3. 710.836

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PATENTEIJJAN 16 1975 SHEET 5 0F 5 INVEN TOR.

BENN IE T. BUSCH m2 R S BARREL STAVE EDGE SAWING MACHINE BACKGROUND OF THE INVENTION l Field of the Invention The present invention relates to power saws and more particularly to a machine for mitering longitudinal side edges of barrel staves, or the like.

In forming barrel staves, billets or tree sections, are simultaneously trimmed at opposing ends to insure equalization of opposing ends of staves to be formed. These billets are then longitudinally divided by sawing, forming a plurality of wedge or substantially triangularshaped sections, which are then cut to form longitudinal transversely arcuate barrel staves progressively increasing in transverse width from the central portion of the tree to its outer surface. The opposing side edges of the partially formed staves may or may not be parallel and must be further processed by mitering to form miter joints with like surfaces of other staves forming a barrel. It is common practice to trim the edges of barrel staves by passing the stave through a power saw to trim one edge of the stave and then positioning the stave on a second power driven saw to trim the opposite longitudinal side. Barrel forming staves vary in width from 3 to inches and thus it is not feasible to provide fixed position saws for simultaneously trimming both edges of such stave. At present this trimming operation is accomplished by visually aligning the stave with the plane of the respective trimming saw. This visual alignment many times results in forming a stave with its side surfaces converging toward one end, thus it must be rejected. Furthermore, under present practice, it normally requires three workmen to operate the two saws and move the staves.

2. Description of the Prior Art Mitering devices are disclosed by U.S. Pat. Nos. 2,673,585; 2,747,629 and 3,49l,805. These patents generally disclose a pair of circular saws arranged with the planes of the saws in downwardly converging relation for mitering opposing sides of staves, or the like. However, the saws of these patents are mounted in a fixed position whereas this invention mounts a pair of saws which are moved toward and away from the respective marginal side edges of a stave to be mitered in response to guide means contacting the marginal side edges of the stave being cut in response to the particular transverse dimension of the stave. Thus, this machine will successively miter opposing sides of a plurality of staves having a like plurality of different transverse dimensions. Furthermore, the machine of this invention may be operated by a single workman.

SUMMARY OF THE INVENTION A horizontal conveyor is supported by a rigid track and moves longitudinally through an upright open frame. A pair of motor driven saws having the planes thereof arranged in downwardly converging relation at one end portion of the frame on respective sides of the conveyor are supported by arms pivotally connected with a remote end portion of the frame so that the saws may be moved toward and away from the conveyor while maintaining the axis of the respective saw perpendicular with respect to the direction of movement of the conveyor. Guide means supported by motor position control arms contact respective marginal side edges of the stave to be mitered as it is moved toward the saw position and adjusts the spacing between the saws in response to the transverse dimension of the stave to be mitered. Spring-urged pressure rollers contacting the upper surface of the stave carried by the conveyor actuates a locking means for maintaining the spacing between the saws at a predetermined position governed by the transverse dimension of the stave being mitered. Passage of the stave off of the conveyor releases the locking means and spring means biases the o saws toward a stop position adjacent the conveyor in position for receiving a succeeding stave to be mitered.

The principal object of this invention is to provide stave side edge trimming saws for simultaneously mitering both sides of a barrel stave wherein the saws are automatically positioned by the transverse dimension of the leading end portion of the stave to be mitered.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the machine in operative position and illustrating a fragmentary leading end portion of a stave to be processed in position for entering the machine;

FIG. 2 is a fragmentary side elevational view, to a smaller scale, of the machine;

FIG. 3 is a top view of FIG. 2;

FIG. 4 is a fragmentary front elevational view of the machine, to an enlarged scale;

FIG. 5 is a fragmentary top view of the forward end of the machine, partially in section, looking in the direction of the arrows 5-5 of FIG. 4;

FIGS. 6 and 7 are vertical cross-sectional views taken substantially along the lines 6-6 and 77, respectively, of FIG. 5;

FIG. 8 is a fragmentary elevational view of the rearward end of the machine; and,

FIG. 9 is a fragmentary vertical cross-sectional view, to a different scale, taken substantially along the line 9-9 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral 10 indicates the device, as a whole, comprising an upright rectangular open frame 12 longitudinally supporting a horizontal conveyor means 14 and including twin pairs of arm means 16 and 18 in turn respectively supporting twin saw means 20 and 22 on opposing sides of the path of the conveyor. The frame 12 comprises a pair of forward vertical legs 24 and 26 joined at their upper ends by a frame top 28 and interconnected intermediate their ends by upper and lower cross members 30 and 32. The rearward end of the frame similarly comprises a pair oflegs 34 and 36 interconnected at their upper limit by top members 38 and intermediate their ends by upper and lower cross braces 40 and 42. The forward and rearward end portions of the frame are interconnected by a pair of side members 44 and 46 in the horizontal plane of the upper cross members 30 and 40. A pair of side rails 48 and 50 interconnect the forward and rearward legs in the plane of the lower cross members 32 and 42.

Referring now more particularly to FIGS. 2, 3, 5 and 7, the conveyor means 14 comprises a conveyor support beam 52 (FIG. 7) extending longitudinally of the central portion of the frame and connected at its respective ends to the forward and rearward cross members 30 and 40. Forward and rearward spacedapart pairs of end plates 54 and 56 are respectively connected to the forward and rearward cross braces 30 and 40 in horizontal alignment with the conveyor support beam 52 to form an extension of the conveyor and respectively journal horizontal forward and rearward axles 58 and 60 coaxially connected with chain sprockets, not shown, which cooperatively engage the links of a chain 62. A friction plate 64 overlies the upper surface of the conveyor beam 52 to form a rigid track surface for slidably supporting the chain 62 as it is progressively moved longitudinally for the purposes presently apparent.

A pair of strap-like chain guides 66 are secured to the respective upper marginal edge surfaces of the conveyor beam 52 to form a conveyor chain receiving channel or guide longitudinally of the frame. A plurality of conveyor plates 68 overlie the conveyor chain 62 in spaced-apart relation and are respectively connected with cooperating links of the chain by lugs 70 secured to the respective plate. The conveyor plates are characterized by their surfaces, opposite the chain, being serrated transversely of the direction of travel of the chain to form teeth facing toward the direction of travel for the purposes readily apparent.

The forward conveyor bearings 59 are mounted on a pair of outer plates 72 secured to the plates 54 by bolts 74 positioned within slots 76 for adjustably maintaining the conveyor chain under tension. The conveyor is driven in the direction of the arrows by a motor 78 mounted on the side rail 48 and connected with a gear train 80. The rearward conveyor shaft 60 projects beyond opposite sides of the conveyor and is journalled at its respective end portions by bearings 82 mounted on stub legs 84 depending from the rearward cross braces 38 (FIG. 8). Belt and pulley means 86 connect the gear train 80 to one end of the conveyor shaft 60. Obviously chain and sprocket means may be used, if desired.

Referring also to FIG. 8, the twin-arm means and twin-saw means 16-18 and -22, respectively, are substantially identical, being mirror images of each other, and in the interest of brevity, only the arm means 16 and saw means 20 will be described in detail. An upper substantially Z-shaped plate 88 overlies and is secured to the rear top braces 38. Similarly a lower plate 90 is secured in vertical spaced aligned relation to the upper surfaces of the rear cross brace 40. An arm support shaft 91 is vertically journalled at its respective ends by bearings 92 and 94 secured to the rearwardly projecting ends of the Z-shaped plates 88 and 90. Upper and lower guide arms 96 and 98 are each secured at one end portion to the respective end portions of the rod support shaft 91 and project forwardly in vertically spaced parallel relation toward the forward end of the frame. Adjacent the forward end of the frame the arms 96 and 98 are connected with a guide ring 100.

A pair of saw means support arms 102 are each connected at one end in vertically spaced parallel relation with a vertical end plate 104 in turn connected with bearings 106 surrounding respective end portions of a vertical shaft 108 journalled by suitable bearings supported by forwardly projecting end portions of the Z- shaped plates 88 and 90.

A motor mount 110. adjustably secured to the housing of an electric motor 112, supports vertically spaced bearings 116 which journal the respective ends ofa vertical shaft 114. The other ends of the pair of arms 102 are respectively connected with bearings I17 surrounding the vertical shaft 114. The arms 102 thus support the motor 112 with its axis adjustably inclined and with one end portion of the motor projecting laterally of the frame through the ring 100. The upper end portion of the vertical shafts 108 and 114 are each coaxially connected with sprockets 118 and 120, respectively, having a chain 122 entrained therearound for the purposes presently described.

The motor 112 is coaxially connected with a circular saw blade 124. The axis of the motor is inclined with respect to the horizontal so that the plane of this saw blade and its oppositely disposed twin are angularly inclined in converging relation downwardly wherein the depending peripheral portion of the saw blades are disposed in predetermined spaced relation with respect to the marginal side edges of the path of the conveyor plates 68 for the purposes presently described.

Referring also to FIGS. 4 and 6, a sensing arm 126 is connected at one end to the guide ring in longitudinal alignment with the guide arm 98 and projects horizontally forward of the forward limit of the frame 12. A header 128 is horizontally connected in perpen dicular relation to the forward end of the sensing arm 126. One end portion 130 of the header projects toward the upper horizontal plane of the conveyor means 14.

A pair of clevis arms 132 are pivotally connected at one end to the header end portion 130 and project horizontally rearward of the frame front toward the motor 112. The rearwardly disposed end portions of the clevis arms 132 are pivotally connected to opposing ends of a first spool 134. A second spool 136 is similarly connected between a pair of ears 138, secured to the sensing arm 126, projecting toward the conveyor. A rod 140 extends horizontally between the spools 134 and 136 and is slidably received by at least one of the spools for movement of the rearward end portions of the clevis arms 132 toward and away from the sensing arm 126 for the purposes presently explained. A helical spring 142 surrounds the rod 140 and normally urges the spool 134 away from the spool 136. A sensing roller or guide wheel 144 is journalled by the clevis arms 132 on a vertical axis intermediate their ends. As stated hereinabove, when in an at rest position the saw blade 124 has its depending peripheral edge portion disposed in predetermined spaced relation with respect to the adjacent marginal side edge of the conveyor plates 68. The rod 140 is adjusted so that the peripheral edge portion of the wheel 144 is disposed further from the conveyor than is the saw blade 124 but spaced away from the adjacent marginal edge of the conveyor plates 68 a selected distance. Stated another way the stave cutting portion of the blade plane 124 is disposed toward the conveyor a selected distance with respect to the vertical plane defined by the peripheral portion of the guide wheel 144 nearest the adjacent edge of the path of travel of the conveyor plates 68.

This distance being predetermined by the width of a strip desired to be severed or cut off of the side edge of a slave 148 to be mitered. This spacing of the guide wheel 144 from the trimming position of the saw blade 124 is adjustably achieved by a bridge arm 150 pivotally connected at one end with the lowermost saw support arm 102. The other end of the bridge arm 150 projects laterally outward of the frame across the upper limit of the guide arm 98 and has a longitudinally extending slot in its free end portion receiving a bolt 152 secured to a suitable lug 154 mounted on the guide arm 98. Resilient means, such as springs 146, respectively, connected with the guide arms 96 bias the saw means toward the conveyor. Thus when a stave 148, to be trimmed, is placed on the conveyor and is moved toward and between the guide wheels 144, a peripheral edge portion of the wheels contact opposing marginal side surfaces of the stave which usually has a transverse width greater than the transverse width of the conveyor plates 68. The guide wheels move the guide arms 96 and 98 laterally of the vertical plane of the conveyor and by means of the bridge arm 150 move the saw blades an equal lateral distance. The axes of the motors 112 and saw blades 124 are maintained perpendicular to the vertical plane of the conveyor during this action by the chain 122 connected with the sprockets 118 and 120 as described hereinabove.

Following the stave trimming action, as more fully described hereinbelow, when springs 146 bias the motors and saws toward the vertical plane of the conveyors an adjustable stop means 155 interrupts this movement. The stop means 155 includes a yoke 156 connected with the outwardly disposed end surface of the motor 112 having a threaded shaft 158 horizontally connected at one end with the yoke and loosely received slidably by an upstanding wing 160 secured at its depending end to the frame side rail 44. A resilient member, such as a section of rubber 162, or the like, surrounds the end portion of the shaft 158 projecting outwardly of the wing 160 to form a bumper or resilient stop.

I have found that the biasing action of the springs 146 and resilient stop means 155 tends to result in a rebounding action of the motor and saw means when biased toward a stop. To avoid this rebounding action cushioning or dampener means 164 is provided which comprises a pump or air cylinder 166 pivotally secured at one end portion with a standard 168 vertically secured to the frame upper cross beam 30 adjacent one side of the conveyor means 14. The shaft or piston rod 170 of the cylinder 166 is adjustably secured to an upstanding bracket ]72 mounted on the header 128. The cylinder 166 contains a piston or cup, not shown, coaxially secured to the inner end of its rod 170. Thus when the motor and saw is biased away from the conveyor, the shaft 170 is pulled outwardly of the cylinder so that air may enter the closed end of the cylinder through an orifice 174. When the motor and saw is biased toward the conveyor, by the springs 146, air within the cylinder 166 is compressed by its piston cup and bled off out of the cylinder through the orifice 174, thus bringing the motor and saw to its predetermined stop position by an air cushion action.

An elongated top rail 176 is connected at one end with the forward frame top member 28 and extends rearwardly of the frame across the upper surface of the frame rearward top members 38 coextensive with the rearward end of the conveyor means 14 and in vertical spaced alignment therewith. A stub rail I78 is com nected at one end with the forward surface of the frame top rail 28 in horizontal alignment with the elongated top rail 176. The top rails I76, and 178 support a force applying means which yieldably engages the workpiece or stave 148 and impinges it against the conveyor plates 68 during the passage of the stave through the frame. The force means comprises a plurality of pressure rollers or wheels aligned edgewise with the rails and including a forward roller 180, an intermediate roller 182 and a rearward roller 184 in close spaced relation with respect to the plane of travel of the upper surface of the conveyor plates 68. The rollers 180 and 182 are journalled between a like plurality of pairs of bracket arms 186 on a horizontal axis with one end portion of the bracket arms being pivotally connected to opposing sides of the top rails 178 and 176, respectively, with the other end of the bracket arms 186 projecting beyond the periphery of the respective roller and connected with the top rail 176 by spring and bolt means 188 normally urging the pressure rollers I and 182 toward the top plane of the conveyor. The rearward pressure roller 184 has one end of its mounting arms pivotally connected with the frame rearward top brace 38 and similarly resiliently connected with the rearwardmost end of the top rail 176. The depending peripheral portion of the respective pressure rollers 180, 182 and 184 are normally maintained, by the resilient bolt and spring means 188, in a predetermined spaced position above the uppermost plane of the conveyor a distance slightly less than the thickness of the stave 148 to be trimmed so that these pressure rollers rollably contact the upper surface of the stave and impinge it against the conveyor plates 68 during the path of travel of the stave through the frame for the purpose of preventing any transverse or lateral movement of the stave with respect to the conveyor and to insure its passage through the machine. A pair of pressure locking rollers 190, only one being shown, are similarly mounted in depending relation with respect to the top rail between the forward pressure roller and intermediate pressure roller 182. The spring urged bolts of the spring and bolt means mounting these pressure locking rollers 190 are respectively connected to the arms of first and second microswitches 192 and 194 mounted on the upper surface of the top rail 176. The microswitches 192 and 194 are electrically connected by wiring, not shown, with a pair of solenoids S (FIG. 4) respectively secured to the forward surface of the frame top cross brace 30 below the arm headers 128. The solenoids each include a plunger 196 which cooperatively engages the teeth of a rack 198 longitudingally secured to the depending surface of the header arms 128 when the solenoids S are energized by closing the microswitches 192 and 194 in the manner presently explained.

As illustrated in FIGS. 1, 2, 4, 8 and 9, the machine further includes a trash or cuttings conveyor means 200 extending longitudinally through the depending portion of the machine in the plane of the frame lower cross members 32 and 42 substantially coextensive with the stave conveyor means 14 and vertically aligned therewith. The conveyor means 200 comprises a belt 202 entrained around forward and rearward pulleys 204 and 206 horizontally journalled by bearings secured to the frame lower cross members 32 and 42 in a manner similar to that described hereinabove for the stave conveyor means 14. The trash conveyor means 200 includes a U-shaped trough member 208 having its bight portion 210 longitudinally secured to a central frame support 212, below the upper span of the belt 202, which extends longitudinally of the frame between the front and rearward frame cross members 32 and 42. The legs 214 of the trough extend upwardly from the plane of the belt 202 in diverging relation a selected distance so that the transverse width, defined by the trough 208, is great enough to form a receptacle for receiving sawdust and strips trimmed off the marginal side edges of the staves being cut so that the conveyor means 200 moves the cuttings out of the confines of the machine at its rearward end. The conveyor belt 202 is driven by belt and pulley means 216 connected respectively with the stave conveyor driving shaft 60 and the axle journalling the rearward conveyor pulley 206. The depending run of the stave conveyor means 14 is protected from sawdust and stave trimmings by an inverted substantially U-shaped guard 218 having its bight portion 220 secured to the depending surface of the conveyor beam 52.

OPERATION In operation the machine 10 is assembled as described hereinabove. The motors 78 and H2 and including the microswitches 192 and 194 are connected with a source of electrical energy by wiring, neither of which are shown. The motor 78 is in operation driving the conveyors l4 and 200 in the direction of the arrows and the motors "2 are driving the saws 124. Conventional conveyor means, not shown, is positioned at the forward and rearward ends of the machine in horizontal alignment with the stave conveyor means 14. Other conveyor means positioned rearwardly of the trash conveyor means 200 moves cuttings away from the machine. In its at rest position, with the saws running, they are positioned adjacent opposing sides of the conveyor plates 68, as illustrated in FIGS. 4 and 8. An operator standing adjacent the forward end of the stave conveyor means 14 manually places a stave 148 to be cut on the forward end of the conveyor means 14 which moves the leading end portion of the stave toward and under the forward pressure roller 180. As the leading end of the stave contacts and passes between the guide wheels 144 these wheels move the saws laterally in opposing directions away from the conveyor by the pivoting arm supports 16-!8 and I02 in accordance with the transverse width of the particular stave. As the leading end edge of the stave passes under and is impinged by the forward locking roller 190 this roller lifts the arm of the forward microswitch 192 to close the contacts of this switch which energizes the solenoids S lifting their plungers 196 into locking contact with the teeth of the racks 198 thus locking the position of the saws for trimming or mitering the respective side edges of the stave 148 as it is moved longitudinally between the saws by the conveyor means 14. Any irregularity in the marginal side edge surfaces of the stave is further compensated for by the resistance of the guide wheel bolt and spring means 140 and 142 permitting the guide wheels 144 to move laterally outward or inward from or toward the position of the conveyor means 14 as the stave 148 continues its travel between these wheels without altering the locked position of the saws. The trailing end edge portion of the stave leaves the position of the forward locking roller 190 before the stave trimming action is complete, however, the rearward locking roller 190, having been lifted by passage of the stave 148, has closed the contacts of the rearward microswitch 194, connected with the solenoids S in parallel with the microswitch 194, thus maintaining the solenoids energized to insure the saws remaining in their previously locked position until such time as the trimmed trailing edge of the stave 148 has been moved beyond the position of the saw blades 124. The intermediate and rearward position pressure rollers 182 and 184 contacting the stave 148 insures that the stave is moved completely through the machine by the conveyor means 14. As soon as the trailing end of the stave has moved beyond the position of the second locking roller 190, the second microswitch contacts are opened by release of the rearwardmost locking pressure roller 190 thus de-energizing the solenoids S which permits the biasing springs 146 to return the saws toward the position of the conveyor means 14 with this action being stopped by the stop means and air cushion resilient means 164 as described hereinabove. Trimmed off portions of the stave fall by gravity through the machine frame and are collected by the trough 208 and moved out of the machine area by the trash conveyor means 200. This completes one cycle of operation.

Obviously the invention is susceptible to changes or alterations without defeating its practicability, therefore, I do not wish to be confined to the preferred embodiment shown in the drawings and described herein.

lclaim: l. A machine for simultaneously mitering opposing sides of a workpiece; comprising:

a frame; twin movable cutting means normally disposed in predermined spatial relationship on said frame;

workpiece supporting conveyor means on said frame including rigid track means passing between said twin cutting means,

said twin cutting means comprising rotary saws having the planes thereof disposed in converging rela tion toward opposing sides of said conveyor adjacent its workpiece supporting surface;

a motor drivably connected with each said saw;

twin sensing means coacting with a workpiece for increasing the spatial distance between said cutting means as a function of the transverse dimension of the workpiece;

suspension arm means on said frame cooperatively supporting said cutting means and said sensing means independently of each other,

said suspension arm means including twin pairs of elongated guide arms pivotally connected in spaced relation at one end with one end portion of said frame and respectively projecting, at their other ends, toward and beyond the respective said motor;

twin pairs of saw support arms pivotally connected in spaced relation with said one end portion of said frame in spaced relation with respect to said respective pairs of guide arms and respectively projecting toward and pivotally connected with said motors;

means adjustably interconnecting said respective pairs of guide arms with the respective pairs of saw support arms;

control means actuated by the passage of a workpiece along said conveyor means for acting on said sensing means and maintaining the increased spatial distance between said twin cutting means for the duration of travel of a workpiece between said cutting means; and,

power means driving said conveyor means.

2. The machine according to claim 1 in which said sensing means includes:

a pair of vertically spaced clevis arms pivotally connected at one end portion, respectively, with the respective end portion of said guide arms projecting beyond said motors;

twin guide wheels respectively journalled on a vertical axis in the plane of the workpiece supporting surface of said conveyor by said clevis arms intermediate their ends; and,

resilient means connecting the other end portions of said clevis arms with the respective said guide arm and normally biasing said wheels toward said conveyor.

3. The machine according to claim 2 in which said 5 control means includes:

a rack secured to the end portion of each said guide arm projecting beyond said motors;

solenoid means secured to said frame adjacent the respective said rack,

said solenoid means including a plunger releasably engaging the respective said rack",

at least one pressure roller journalled by said frame on a horizontal axis for movement toward and away from the workpiece supporting surface of said conveyor;

a normally open switch mounted on said frame above said pressure roller;

means connecting said pressure roller with said switch for closing said switch in response to movement of said pressure roller away from the workpiece supporting surface of said conveyor; and,

wiring connecting said switch and said solenoid means with a source of electrical energy.

i It I III 

1. A machine for simultaneously mitering opposing sides of a workpiece; comprising: a frame; twin movable cutting means normally disposed in predermined spatial relationship on said frame; workpiece supporting conveyor means on said frame including rigid track means passing between said twin cutting means, said twin cutting means comprising rotary saws having the planes thereof disposed in converging relation toward opposing sides of said conveyor adjacent its workpiece supporting surface; a motor drivably connected with each said saw; twin sensing means coacting with a workpiece for increasing the spatial distance between said cutting means as a function of the transverse dimension of the workpiece; suspension arm means on said frame cooperatively supporting said cutting means and said sensing means independently of each other, said suspension arm means including twin pairs of elongated guide arms pivotally connected in spaced relation at one end with one end portion of said frame and respectively projecting, at their other ends, toward and beyond the respective said motor; twin pairs of saw support arms pivotally connected in spaced relation with said one end portion of said frame in spaced relation with respect to said respective pairs of guide arms and respectively projecting toward and pivotally connected with said motors; Means adjustably interconnecting said respective pairs of guide arms with the respective pairs of saw support arms; control means actuated by the passage of a workpiece along said conveyor means for acting on said sensing means and maintaining the increased spatial distance between said twin cutting means for the duration of travel of a workpiece between said cutting means; and, power means driving said conveyor means.
 2. The machine according to claim 1 in which said sensing means includes: a pair of vertically spaced clevis arms pivotally connected at one end portion, respectively, with the respective end portion of said guide arms projecting beyond said motors; twin guide wheels respectively journalled on a vertical axis in the plane of the workpiece supporting surface of said conveyor by said clevis arms intermediate their ends; and, resilient means connecting the other end portions of said clevis arms with the respective said guide arm and normally biasing said wheels toward said conveyor.
 3. The machine according to claim 2 in which said control means includes: a rack secured to the end portion of each said guide arm projecting beyond said motors; solenoid means secured to said frame adjacent the respective said rack, said solenoid means including a plunger releasably engaging the respective said rack; at least one pressure roller journalled by said frame on a horizontal axis for movement toward and away from the workpiece supporting surface of said conveyor; a normally open switch mounted on said frame above said pressure roller; means connecting said pressure roller with said switch for closing said switch in response to movement of said pressure roller away from the workpiece supporting surface of said conveyor; and, wiring connecting said switch and said solenoid means with a source of electrical energy. 